College of Chemistry, Beijing Normal University, Beijing, 100875, China.
Phys Chem Chem Phys. 2011 Aug 14;13(30):13721-9. doi: 10.1039/c1cp20522f. Epub 2011 Jun 28.
The spectroscopic methods UV-Vis absorption, FT-IR and (13)C and (19)F NMR demonstrate that 1,2-diiodoperfluoroethane (DIPFE) and 1,6-diiodoperfluorohexane (DIPFH) display strong halogen bonding with halide anions. A 1 : 1 stoichiometry of DIPFE or DIPFH with halide anion is confirmed, and the bonding constants and molar extinction coefficients are obtained. With the same halide, DIPFH possesses greater bonding constants and molar extinction coefficients than DIPFE. Furthermore, the bonding constants present in this article are far greater than those of all halogen bonding complexes reported. Interestingly, the FT-IR spectrum indicates that halogen bonding promotes a conversion from gauche to trans conformer of DIPFE. The X-ray data further confirm a 1 : 1 stoichiometry and all DIPFE and DIPFH exist in trans conformers in cocrystals which were assembled with halide anions. As potential persistent organic pollutions, iodinated perfluoroalkanes have been paid much attention. The present study will benefit current research of their separation and recognition in environmental samples.
光谱方法 UV-Vis 吸收、FT-IR 和 (13)C 和 (19)F NMR 表明，1,2-二碘全氟乙烷 (DIPFE) 和 1,6-二碘全氟己烷 (DIPFH) 与卤化物阴离子显示出很强的卤素键合作用。证实了 DIPFE 或 DIPFH 与卤化物阴离子的 1:1 化学计量比，并获得了键合常数和摩尔消光系数。对于相同的卤化物，DIPFH 的键合常数和摩尔消光系数大于 DIPFE。此外，本文中的键合常数远远大于所有报道的卤素键合配合物的键合常数。有趣的是，FT-IR 光谱表明卤素键合促进了 DIPFE 从 gauche 构象向 trans 构象的转变。X 射线数据进一步证实了 1:1 的化学计量比，并且在与卤化物阴离子组装的共晶中，所有 DIPFE 和 DIPFH 都以 trans 构象存在。作为潜在的持久性有机污染物，碘代全氟烷烃受到了广泛关注。本研究将有助于当前对其在环境样品中分离和识别的研究。
